Numbers

Real numbers in the netlist file can be represented as decimal, exponential, or scaled numbers, or as decibels (exponentially scaled numbers).

A decimal number consists of the numerals 0 through 9, with or without a decimal point, and with or without a leading unary plus or minus: 123, 12.30, +5.0, -20.

An exponential number consists of a decimal number mantissa, the letter e (for “exponent”) and a decimal number exponent. The decimal equivalent is the mantissa multiplied by 10 to the power of the exponent.

A scaled number consists of a decimal number and an alphabetic token representing a scale factor: 20K, 1.5P, -7.25MEG. The following table lists the scale factor tokens and their exponential equivalents.

Note: By default, the single-letter token “A” as a numeric suffix represents amperes (AMP). If the netlist contains the statement .OPTIONS UNIT_ATTO, the single-letter suffix “A” represents
1e-18 (ATTO). In either case, the token AMP (with or without any trailing characters) is interpreted as amperes, and the token ATTO (with or without any trailing characters) is interpreted as 1e-18.

A decibel number uses one of the units DB or DBM. A number (nn in the following examples) with one of these units scales exponentially:

nnDB is scaled as 10 ^ (nn * 0.1).

nnDBM is scaled as 10 ^ (nn * 0.1 - 3).

In both of these examples, the ^ sign denotes exponentiation and the * sign denotes multiplication.

Note: Any extra letters after the DB or DBM prevent a match for DB or DBM (unlike other units, where additional letters are ignored). Here are some examples:

5K = 5000

5KOHM = 5000

5KAPPLES = 5000

5DB = 3.1622777

5DBW = 5

5DBM = 0.0031622777

5DBMW = 5